1.1 本试验方法涵盖了使用稀释并将取样天然气与空气混合的仪器确定天然气的阈值检测水平、易检测水平和气味强度的程序。然后，操作员对混合气流进行嗅探，以确定天然气流中加臭剂的任何这些参数。 1.2 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.3 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 联邦法规（49 CFR第192.625部分）规定:“配电线路中的可燃气体必须含有天然加臭剂或经过加臭处理，以便在空气中的浓度为爆炸下限的五分之一时，具有正常嗅觉的人容易检测到该气体。”这些法规进一步规定，“为了确保本节中有适当的加臭剂浓度，每个操作员必须使用能够确定空气中气味易于检测的气体百分比的仪器对可燃气体进行定期采样。”此外，一些州已颁布立法，要求对天然气进行加臭处理，使其在低于爆炸下限五分之一的浓度下可检测到。 看见 注1 . 虽然法规没有规定确定依从性的确切方法，但有文件证明，依从性测试必须是嗅觉性质的。 4. 注1: 例如，马萨诸塞州第192.625节MFS标准要求:“空气中百分之一百五十一的气体浓度很容易被人的正常或平均嗅觉感知到。” 4.2 本试验方法涵盖了通过嗅觉测定来测量天然气气味水平的程序。本试验方法与现有或正在开发的定量测量天然气中硫化物浓度的方法之间不存在直接相关性。 4.3 本试验方法概述了测量天然气气味检测水平的一般程序。 使用本试验方法的人员有责任开发和维护设备和特定操作程序，以确保公共安全和遵守所有适当法规。

1.1 This test method covers the procedures for determining the threshold detection level, readily detectable level, and odor intensity of natural gas using instruments that dilute and mix the sampled natural gas with air. The mixed gas stream is then sniffed by the operator for the purpose of determining any of these parameters for odorant in a natural gas stream. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 Federal regulations (49 CFR Part 192.625) state: “A combustible gas in a distribution line must contain a natural odorant or be odorized so that at a concentration in air of one-fifth of the lower explosive limit, the gas is readily detectable by a person with a normal sense of smell.” These regulations state further that “To assure the proper concentration of odorant with this section, each operator must conduct periodic sampling of combustible gases using an instrument capable of determining the percentage of gas in air at which the odor becomes readily detectable.” Additionally, a number of states have enacted legislation that requires natural gas to be odorized so that it is detectable at concentrations less than one fifth of the lower explosive limit. See Note 1 . While regulations do not specify the exact method for determining compliance, it has been documented that compliance testing must be olfactory in nature. 4 Note 1: For example, Massachusetts Section 192.625 MFS Standards requires that “. a concentration of fifteen hundredths of one percent gas in the air is readily perceptible to the normal or average olfactory senses of a person.” 4.2 This test method covers procedures to measure the odor level of natural gas by way of olfactory determination. No direct correlation may be ascertained between this test method and those methods available or under development that quantitatively measure the concentration of sulfur compounds in natural gas. 4.3 This test method outlines general procedures to measure the odor detection levels of natural gas. It is the responsibility of persons using this test method to develop and maintain equipment and specific operating procedures to ensure public safety and compliance with all appropriate regulations.